INDIGENOUS FOEE8TS. 99 



The soil of the forest of Fontainbleau is composed almost entirely 

 of sand, interspersed with ledges of rook. The sand forms ninety- 

 eight per cent, of the earth, and it is almost without water ; it would 

 be a drifting desert but for the trees growing and artifically propa- 

 gated upon it. 



In reference to such superficial sand formations, the following 

 remarks are made by Wessley : 



" It is scarcely to be supposed that all inland sand drifts have 

 been lying exposed, and drifted about since anti-diluvian times. On 

 the contrary, we find almost everywhere that diluvial sands, by a 

 slow but ever advancing natural process, become gradually covered 

 with herbage, and ultimately with bush or forest, whereby they 

 become so fixed as to be unmoved by the wind. And this process 

 goes on all the more rapidly if man do not disturb it — if he do not 

 promote it. 



" And what has been effected thus in pre-historic times, is both 

 denser and more during that what has been effected in later years : 

 as the soil of that is richer in humus than is any planted by the hand 

 of man. And these oldest plant-bearing sands may be described, as 

 we sometimes describe nations, as the aboriginal vegetation of the 

 ground on which they are found." Such seems to be the case with 

 the oak forest of Fontainbleau. 



Other forests growing indigenously on sands of the tertiary 

 formation might be cited ; but it is considered that one case of such 

 is sufficient to show that forests may be produced and grow 

 permanently on sands, and to give some idea of appearances pro- 

 duced by these. 



What was at one time in the world's history, the natural state of 

 these lands of La Sologne, a country more or less covered with forest 

 trees, is what sylviculture is seeking to reproduce there, and to pro- 

 duce artificially on the Landes of Gascony and elsewhere ; and what 

 has been effected by self-sown seed may be effected again by artificial 

 culture, if the natural history of the trees employed be known. 



We have seen the good effect with which this has been done in 

 Belgium, and on the Landes of the Gironde and of Gascony ; and with 

 what similar effect it has been done on the Landes of La Sologne. By 

 Jules Clave, a student of forest science of world-wide fame, it is stated 

 in a paper in the Revue des Deux Mondes for March, 1866, that the 

 district of Sologne, flat and marshy as it is, was salubrious until its 

 forests were felled. It then became pestilential, but of late years its 

 healthfulness has been restored with its forest plantations. 



